The construction of log structures by the method of notching logs so that they interfit with each other is well known. Logs have long been notched transversely near their ends so as to allow such logs to be interfitted at corners, thus allowing the longitudinal span of consecutive logs, on progressively elevated courses, to lie in closer proximity to each other. Logs have also been grooved longitudinally to allow logs resting directly on top of each other to be more closely interfitted.
In the case of transverse notches used in traditional log cabins having singularly notched logs laying over round logs, the notches have been shaped to a round profile. Such a single rounded notch generally has a depth of about one-half of the log diameter. When complementary notches in crossing logs have been employed, such notches have customarily been rectangular in cross-section. Notches in this case are about one-quarter of the log diameter in depth. An example of notching in this latter form is shown in U.S. Pat. No. 2,059,598 to N. J. Paulson. Triangular or "V" shaped notches adapted to allow intersecting courses of rectangular logs (oriented with their diagonals in the vertical plane) to be interfitted have also been proposed. An example in this latter category is U.S. Pat. No. 2,669,060 to Kalvig.
To allow logs to be interfitted longitudinally, use of an extended longitudinal tongue or tenon has been proposed. Such a tenon may be milled or fitted into a log along its length. This longitudinal tenon, positioned on the upper side of one course of logs, is arranged to interfit into a complementary longitudinal groove formed in the lower side of the next above course of logs. Such an arrangement is shown in U.S. Pat. No. 2,238,039 to De Witt.
The prior art does not show, however, an arrangement by which courses of logs of rectangular cross-section are longitudinally interfitted directly into each other without the necessity of forming a specially shaped tenon along the length of the individual logs.
This invention is directed to a means by which logs may be shaped so as to be so interfitted longitudinally, without the formation of a tenon by a supplementary operation, or by any operation other than the squaring of the log. These and other features of the invention will become apparent from the description of the invention which now follows.